The present invention is directed to a system and method for determining without recruiting vehicles, or physically or electronically connecting to vehicle systems, whether the emission systems of in-use vehicles perform according to the regulatory standards by which they were initially certified, and in particular whether particular models of vehicles are performing to their regulatory standard.
In-use vehicle emissions testing typically involves recruiting such in-use vehicles from active service and testing them on driving simulators at set conditions, such as with respect to engine load and RPMs, and/or performed when vehicle exhaust systems or computers are connected with portable emissions measurement testing equipment while the vehicle is driven on the road. These testing techniques include connections to the vehicle that are potentially detectable by the vehicle. In certain instances, vehicle manufacturers have manipulated vehicle emissions control systems, such as software controls, to circumvent the emissions controls when the vehicle on board computer system detects the vehicle is in normal on-road use, as compared to performing a regulatory compliance test drive. For example, vehicle software has been improperly configured to deactivate particular emissions equipment or functions during regular driving conditions. Such circumventions, which are generally referred to as defeat devices, violate emissions regulations and are employed to improperly obtain performance gains.